The present invention is directed to fine-mechanical adjusting devices and especially an adjusting device in which adjustment is performed by rotating an adjusting part with external threads inside a sleeve with internal threads. This type of adjusting device is commonly used in optical applications, for example, in which the position of a lens, an optical fiber or some other optical component must be precisely adjusted.
It is common knowledge that distance adjustment by means of threaded parts is problematic due to backlash in the threads, and that adjusting accuracies of one micrometer are obtainable with the most expensive manufacturing methods. However, in practical applications, it has proved to be very difficult to reach such accuracies at reasonable cost. Therefore, distance adjustment based on other technologies, such as thermal expansion or piezoelectric elements, often must be used to reach adjusting accuracies of one nanometer in, for example, optical applications requiring very accurate adjustment, such as laser measuring devices. Adjustment realized with a piezoelectric element, for example, requires an electronic unit connected to the element, raising the cost of the realization.
Therefore, it would be quite desirable if a simple, inexpensive solution for distance adjustment based on threaded parts were available, making it possible to obtain adjusting accuracies of 0.001 mm or even better, and offering backlash-free adjustment, sufficient adjusting sensitivity and good directional stability during adjustment. In many cases, said adjustment would replace a more complicated and costly adjustment, and said adjustment is also needed as a course adjustment in applications using even finer adjusting methods for final adjustment. The object of the present invention is to present said adjustment solution based on threaded parts.